Support TCP keepalives in geard

Support configuration of TCP keepalives in gear server.
When connections are closed not gracefully they stays opened
for a long time, which leads to file descriptors leak.
Default values for interval, probe and count are such as in
most Linux distributions.
By default is disabled to keep compatibility with older versions.

Change-Id: I335f68a24dda409b1a48c6e4e520ec08dfd38078

2 files changed, 33 insertions, 2 deletions

diff --git a/gear/__init__.py b/gear/__init__.py
index f775d83..e03f3d0 100644
--- a/gear/__init__.py
+++ b/gear/__init__.py
@@ -2424,6 +2424,10 @@ class Server(BaseClientServer):
         access control rules to its connections.
     :arg str host: Host name or IPv4/IPv6 address to bind to.  Defaults
         to "whatever getaddrinfo() returns", which might be IPv4-only.
+    :arg bool keepalive: Whether to use TCP keepalives
+    :arg int tcp_keepidle: Idle time after which to start keepalives sending
+    :arg int tcp_keepintvl: Interval in seconds between TCP keepalives
+    :arg int tcp_keepcnt: Count of TCP keepalives to send before disconnect
     """
 
     edge_bitmask = select.EPOLLET
@@ -2433,7 +2437,8 @@ class Server(BaseClientServer):
 
     def __init__(self, port=4730, ssl_key=None, ssl_cert=None, ssl_ca=None,
                  statsd_host=None, statsd_port=8125, statsd_prefix=None,
-                 server_id=None, acl=None, host=None):
+                 server_id=None, acl=None, host=None, keepalive=False,
+                 tcp_keepidle=7200, tcp_keepintvl=75, tcp_keepcnt=9):
         self.port = port
         self.ssl_key = ssl_key
         self.ssl_cert = ssl_cert
@@ -2462,6 +2467,15 @@ class Server(BaseClientServer):
                 self.socket = socket.socket(af, socktype, proto)
                 self.socket.setsockopt(socket.SOL_SOCKET,
                                        socket.SO_REUSEADDR, 1)
+                if keepalive:
+                    self.socket.setsockopt(socket.SOL_SOCKET,
+                                           socket.SO_KEEPALIVE, 1)
+                    self.socket.setsockopt(socket.IPPROTO_TCP,
+                                           socket.TCP_KEEPIDLE, tcp_keepidle)
+                    self.socket.setsockopt(socket.IPPROTO_TCP,
+                                           socket.TCP_KEEPINTVL, tcp_keepintvl)
+                    self.socket.setsockopt(socket.IPPROTO_TCP,
+                                           socket.TCP_KEEPCNT, tcp_keepcnt)
             except socket.error:
                 self.socket = None
                 continue
diff --git a/gear/cmd/geard.py b/gear/cmd/geard.py
index 762d956..d35dc25 100644
--- a/gear/cmd/geard.py
+++ b/gear/cmd/geard.py
@@ -60,6 +60,18 @@ support.
                             help='path to SSL private key')
         parser.add_argument('--acl', dest='acl', metavar='PATH',
                             help='path to ACL file')
+        parser.add_argument('--keepalive', dest='keepalive', default=False,
+                            action='store_true',
+                            help='enable TCP keepalives in socket')
+        parser.add_argument('--keepalive-idle', dest='tcp_keepidle', type=int,
+                            default=7200, action='store',
+                            help='TCP keepalive idle time')
+        parser.add_argument('--keepalive-interval', dest='tcp_keepintvl', type=int,
+                            default=75, action='store',
+                            help='TCP keepalive probe interval')
+        parser.add_argument('--keepalive-count', dest='tcp_keepcnt', type=int,
+                            default=9, action='store',
+                            help='TCP keepalive probes count')
         parser.add_argument('--version', dest='version', action='store_true',
                             help='show version')
         self.args = parser.parse_args()
@@ -109,7 +121,12 @@ support.
                                   statsd_host,
                                   statsd_port,
                                   statsd_prefix,
-                                  acl=acl)
+                                  acl=acl,
+                                  keepalive=self.args.keepalive,
+                                  tcp_keepidle=self.args.tcp_keepidle,
+                                  tcp_keepintvl=self.args.tcp_keepintvl,
+                                  tcp_keepcnt=self.args.tcp_keepcnt
+                                  )
         signal.pause()